Two-stage plate rotary vacuum pumps



Dec. 28, 1965 N. P. JANENKOV TWO-STAGE PLATE ROTARY VACUUM PUMPS 3 Sheets-Sheet 1 Filed July 12, 1963 1366- 23, 1955 N. P. JANENKOV 3,226,014

TWO-STAGE PLATE ROTARY VACUUM PUMPS Filed July 12, 1965 5 Sheets-Sheet z Dec. 28, 1965 JANENKQV 3,226,014

TWO-STAGE PLATE ROTARY VACUUM PUMPS Filed July 12, 1963 3 Sheets-Sheet 5 United States Patent Ofifice I 3226,014 Patented Dec. 28, 1965 3,226,014 TWO-STAGE PLATE ROTARY VACUUM PUMPS Nikolai Petrovich Janenkov, Varshavskoe Chaussee, 153, Block I, Apt. 16, Moscow, U.S.S.R. Filed July 12, 1963, Ser. No. 294,566 4 Claims. (Cl. 230-158) The present invention relates to vacuum pumps, and more particularly to two-stage vacuum pumps embodying a rotor provided with vanes.

Heretofore the pumps of this general type have included housings filled to a certain level with oil and such housings contained immovable working chambers or spaces having pre-rated clearances, a rotor provided with vanes arranged in the chambers and adapted to be actuated through a pulley rigidly connected with a continuation or extension of the rotor. The speed of rotation of such rotors is limited due to friction of the vanes against the immovable inner surfaces of the working chambers, since increased rotor revolutions cause oil cracking and impair the vacuum created by the pump. An increased efficiency of such pumps can be attained by enlarging the volume of the working chambers and, consequently, the overall dimensions of the pump and its weight.

Attempts have been made for the purpose of reducing friction, to utilize in vacuum pumps the elements of known fluid-flow engines, wherein the working chambers were formed by rings supporting the rotor vanes and which rotate together with the rings in the same direction. However, the provision of rings for two open faced surface does not ensure the necessary fluid-tightness of working chambers and such pumps failed to create the pre-rated residual pressure (vacuum).

The main object of this invention is to overcome the above enumerated defects.

Another object of the invention is the provision of a vacuum vane rotor pump, preferably of two-stage type which, while having the same overall dimensions as other known pumps, assures a high efficiency and reliable operation thereof.

More particularly, the present vacuum pump comprises a housing, two coaxially and oppositely arranged sleeves within the housi g, a bushing rigidly mounted between the sleeves in the housing with such sleeves and bushing constituting rotary working chambers within the housing. Each sleeve has an end face and a shaft rigidly connected to such end face rotatably mounted within the housing and having pre-rated clearances filled with oil necessary to ensure sealing of the pump with one of the shafts constituting the driving shaft.

A rot-or is mounted eccentrically respecting the axis of rotation of the sleeves and the bushing in the housing defines the rotor bearing and isolates the working chambers from one another and the bushing is provided with a duct ensuring the formation of the twin stages of the pump during successive connection of the chambers, and also ducts for the inlet and outlet of the transferred medium.

The rotor is provided with slots at each ring with the slots preferably being arranged at an angle of 90 to each other and spring-cushioned vanes are disposed in .the rotor slots. Two of the vanes are jointly secured on the inner side of an end face of each sleeve in such a manner that rotation of the sleeve having the driving shaft connected with the mentioned vane, which in turn is jointly connected with the inner side of an end face of such sleeve assures rotation-of the rotor and the latter via the second vane jointly connected with the inner side ofan end face of the second sleeve rotates such second sleeve. In this way, the present pump with oil sealing increases considerably the number of rotor revolutions and consequently raises the efficiency thereof, as compared with other known pumps of this type.

Additional objects and advantages of the invention will become more readily apparent to persons skilled in the art from the ensuing detailed specification and annexed drawings, in which drawings:

FIG. 1 is a view in vertical cross-section, with certain parts in elevation, of the present pump.

FIG. 2 is a view taken along line A-A in FIG. 1.

FIG. 3 is a prespective view of the bushing showing the gas flow direction.

FIG. 4 is a perspective view of the rotor.

FIGS. 5 and 6 are perspective views of the springcushioned vanes.

FIG. 7 is a view showing the changing volumes in the working chamber of the second stage in which the volume V of the suction space isequal to the volume V of the exhaust space.

FIG; 8 is a similar view showing the increase of the suction space by the gas coming from the first stage of the pump.

FIG. 9 is a view showing the followingincrease of the volume V and the simultaneous decrease of the volume V'.

FIG. 10 is a view showing the volume V being connected with the volume V and volume V" of the suction space.

FIG. 11 is a view showing the volume V equalling zero, the initial stage of volume V decreasing and volume V" increasing.

FIG. 12 is a view showing the following increasing of volume V' and its fulfillment by the gas emanating from the first stage of the pump and with volume V decreasing, and

FIG. 13 is a view showing volume V" of the suction space equalling volume V of the exhaust space.

The present pump, as shown in FIGURE 1, comprises a housing 1 having clearances S and S.

A rotor 3 provided with spring-cushioned plates 4, 5 (FIG. 6) and 4', 5' is eccentrically arranged within sleeves 2 and 2' with the eccentricity being shown at e. The sleeves 2 and 2' are positioned within the housing 1 coaxially and oppositely and the sleeves are rigidly connected with shafts 6 and 6 respectively with the shaft 6 constituting the driving shaft. The shafts 6 and 6' are rotatably mounted in the end walls of the housing 1 as illustrated in FIG. 1. The end faces of the sleeves 2 and 2 from their inner sides are provided with blind cylindrical holes 7 and 7', respectively. The clearances S and S serve for filling the housing 1 with oil necessary for assuring sealing of the pump.

A bushing 9 is pressed into an intermediate piece 8 of the housing and serves as a bearing for the rotor 3 as well as assisting in isolating the sleeve 2 from the sleeve 2. The sleeves 2 and 2' together with shafts 6 and 6 and bushing 9 constitute the working chambers. As best shown in FIGURE 3, the bushing 9 is provided with a duct 10 for ensuring, during the successive connection of chambers 2 and 2', the formation of the two stages of the pump with-the chamber 2' being the first stage and the chamber 2 the second stage. The bushing 9 is further formed with two ducts 11 and 12 for the inlet and outlet of the pumping gas, as shown in FIGURES 2 and 3.

As clearly illustrated in FIGURES 4-6, the rotor 3 is provided with slots 13 and 13' at its respective ends, with such slots being arranged at an angle of 90 respecting each other. The pairs of vanes are provided with cylindrical shanks 14 and 14 on their side faces for fitting into the blind cyclindrical holes 7 and 7' of the sleeves 2 and 2' (FIG. 1).

During pump operation, the shaft 6 (FIGS. 1 and 2) and sleeve 2 of the second stage initially have rotary movement imparted thereto and the sleeve 2 transmits such rotary movement to the rotor through the shank 14 of the vane 4. In turn, the rotor 3 transmits rotary movement to the sleeve 2' of the first stage via the shank 14' of the vane 4.

The pumping out gas which flows through an inlet 15 and a duct 16 formed in the intermediate piece 8 and the duct 11 of the bushing 9 passes into the space of the sleeve 2' constituting the first stage of the pump. When the rotor 3 turns from to 360, the gas from the first stage space passes through the duct 10 and enters the second stage of the pump constituted by the sleeve 2 wherein the cycle is repeated.

Following the above, the gas passes throught the outlet duct 12 of the bushing to an exhaust valve (not shown) which is mounted in the intermediate piece 8 and is forced from the second stage into the space of the housing 1 which is filled with oil and therefrom through an oil separator 17 to the ambient atmosphere. To show more clearly the direction in which the transferred fluid moves, attention is called to arrows B, C and D in FIG- URES 1 and 2.

For applying a suitable lubricant such as grease, to the friction surfaces of the rotor and vanes, as well as for ensuring a proper seal between the rotor vanes and the sleeves 2 and 2, an aperture or bore 18 is provided (FIGURE 1), with such bore communicating respectively with the space in the housing 1 and an annular groove formed in the rotor 3. The clearances in the working chambers 2 and 2 can be adjusted by means of a set of metal washers 19 positioned about the shafts 6 and 6 adjacent the end faces of the respective sleeves.

Moreover, for assuring fluid-tightness of the working chambers 2 and 2, two heat treated steel rings 20 and washers 21 of oil proof rubber are provided between the periphery of the bushing 9 and the respective open ends of the sleeves 2 and 2.

Referring now to FIGURE 7, during rotation in the direction indicated by the arrows E and F of the sleeve 2 and the rotor 3 with the vanes 4 and from 0 to 360 due at the off-center position e FIG. 8 between the axes of the sleeve and rotor, there occurs in inconsiderable slipping of the vane 5 in the area where it contacts the sleeve 2 with such area being limited by angle on.

FIGS. 7-13 denotes seven positions of the sleeve and rotor and illustrates the change of volumes in the working chamber for the second stage of the pump when the sleeve and rotor rotate from 0 to 180 with an interval of 30. FIG. 7 shows volume V of the suction space equalling volume V of the exhaust space. When the sleeve 2 turns through an angle of 30 (FIG. 8), the volume of the suction space increases and becomes filled with gas flowing from the first stage of the pump through the duct 10, and meanwhile volume V decreases, as a result of which the transferred gas is forced from the second stage through the duct 12. When the sleeve 2 turns through an angle of 60 (FIG. 9), a further increase of the volume V and a decrease of the volume V takes place, namely, the transferred gas is forced from the second stage of the pump.

With reference to FIG. 10, upon turning of the sleeve 2 through an angle of 90, the volume V is disconnected from the duct and connected with the space V through the duct 12, at which time gas fiows in from the first stage through the duct 10 and fills volume V of the suction space. When the sleeve 2 turns through an angle of as shown in FIG. 11, the volume V equals zero with a decrease of volume V and an increase of volume V", thereby initiating a new cycle of pump operation whereby volume V of the first stage receives transferred gas through the duct 10 while from volume V the transferred gas is forced through the duct 12.

As disclosed in FIG. 12, upon the sleeve 2 turning through an angle of a further increase of the volume V" occurs with its filling with gas being effected through duct 10 of the first stage, while volume V decreases, namely, the forcing of gas from the second stage through the duct 12 continues to occur. When the sleeve 2 turns through an angle of as illustrated in FIG. 13, volume V" of the suction space equal-s volume V of the exhaust space, i.e., similar to FIG. 7.

It will be obvious to those skilled in the art that various changes may be made in the invention without departing from the spirit and scope thereof and therefore the invention is not limited by that which is shown in the drawings and described in .the specification, but only as indicated in the appended claims.

I claim:

1. A vacuum pump, particularly of the two-stage type, comprising a housing, two coaxially and oppositely arranged rotatable sleeves within the housing, a bushing rigidly mounted in said housing between said sleeves, said sleeves and bushing constituting working chambers, each sleeve having a closed end, a shaft rigidly secured to each closed end for mounting the sleeves within the housing with pre-rated clearances filled with oil for ensuring pump sealing, one of said shafts defining a driving shaft, a rotor mounted within said sleeves eccentrically to the axis of rotation of said sleeves, said bushing in said housing serving as a rotor bearing and isolating said working chambers from each other, said bushing being provided with duct means defining the two pump stages during successive connection of the working chambers and ducts for the inlet and outlet of the transferred medium, said rotor having a slot at each end thereof, said slots being arranged at an angle of 90 relative to each other, spring-cushioned vanes arranged in each slot, and two of said vanes being jointly coupled to the inner surface of each sleeve so that during rotation of the sleeve having the driving shaft secured to said vane jointly coupled to the inner surface of said sleeve, rotation is imparted to the rotor and from the rotor to the other sleeve via the vane jointly coupled to the inner surface of the closed end of the other sleeve.

2. A vacuum pump, particularly of the two-stage type, comprising a housing, two coaxially and oppositely arranged rotatable sleeves within the housing, a bushing rigidly mounted in said housing between said sleeves, said sleeves and bushing constituting working chambers, each sleeve having a closed end, a shaft rigidly secured to each closed end for mounting the sleeves within the housing with pre-rated clearances filled with oil for ensuring pump sealing, one of said shafts defining a driving shaft, a rotor mounted within said sleeves, eccentrically to the axis of rotation of said sleeves, said bushing in said housing serving as a rotor bearing and isolating said working chambers from each other, said bushing being provided with duct means defining the two pump stages during successive connection of the working chambers and ducts for the inlet and outlet of the transferred medium, said rotor having a slot at each end thereof with such slots being arranged at an angle of 90 relative to each other, spring-cushioned vanes arranged in each slot, the inner surface of the closed end of each sleeve having a blind hole therein, and a shank on each vane fitted into said blind hole so that during rotation of the sleeve having the driving shaft rotation is imparted to the rotor via the shank and vane and from the rotor to the other 1,695,650 12/1928 Godillot 103-121 sleeve via its vane and shank. 1,712,935 5/ 1929 Seaholm 103121 3. The vacuum pump as claimed in claim 2 including 1,712,936 5/1929 Seaholm 103121 means cooperable with each shaft and the housing for 1,869,787 8/1932 Trurnble 230-140 adjusting the clearances in the working chambers. 5

4. The vacuum pump as claimed in claim 3 in which FOREIGN PATENTS said adjusting means is defined by a set of metal washers. 394,263 6/ 1933 Great Britain.

References Cited by the Examiner DONLEY I. STOCKING, Primary Examiner.

UNITED STATES PATENTS 1o WILBUR I. GOODLIN, JOSEPH H. BRANSON, JR., 677,122 6/1901 Dow 230 140 Examiners- 724,665 4/1903 Cooley 103-121 

1. A VACUUM PUMP, PARTICURLARLY OF THE TWO-STAGE TYPE, COMPRISING A HOUSING, TWO COAXIALLY AND OPPOSITELY ARRANGED ROTATABLE SLEEVES WITHIN THE HOUSING, A BUSHING RIGIDLY MOUNTED IN SAID HOUSING BETWEEN SAID SLEEVES, SAID SLEEVES AND BUSHING CONSTITUTING WORKING CHAMBERS, EACH SLEEVE HAVING A CLOSED END, A SHAFT RIGIDLY SECURED TO EACH CLOSED END FOR MOUNTING THE SLEEVES WITHIN THE HOUSING WITH PRE-RATED CLEARANCES FILLED WITH OIL FOR ENSURING PUMP SEALING, ONE OF SAID SHAFTS DEFINING A DRIVING SHAFT, A ROTOR MOUNTED WITHIN SAID SLEEVES ECCENTRICALLY TO THE AXIS OF ROTATION OF SAID SLEEVES, SAID BUSHING IN SAID HOUSING SERVING AS A ROTOR BEARING AND ISOLATING SAID WORKING CHAMBERS FROM EACH OTHER, SAID BUSHING IN SAID PROVIDED WITH DUCT MEANS DEFINING THE TWO PUMP STAGES DURING SUCCESSIVE CONNECTION OF THE WORKING CHAMBERS AND DUCTS FOR THE INLET AND OUTLET OF THE TRANSFERRED MEDIUM, SAID ROTOR HAVING A SLOT AT EACH END THEREOF, SAID SLOTS BEING ARRANGED AT AN ANGLE OF 90* RELATIVE TO EACH OTHER, SPRING-CUSHIONED VANES ARRANGED IN EACH SLOT, AND TWO OF SAID VANES BEING JOINTLY COUPLED TO THE INNER SURFACE OF EACH SLEEVE SO THAT DURING ROTATION OF THE SLEEVE HAVING THE DRIVING SHAFT SECURED TO SAID VANE JOINTLY COUPLED TO THE INNER SURFACE OF SAID SLEEVE, ROTATION IS IMPARTED TO THE ROTOR AND FROM THE ROTOR TO THE OTHER SLEEVE VIA THE VANE JOINTLY COUPLED TO THE INNER SURFACE OF THE CLOSED OF THE OTHER SLEEVE. 